<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        ul {
            margin: 0;
            padding: 0;
            list-style: none;
        }

        ul li {
            width: 400px;
            height: 400px;
        }

        ul li:first-child {
            background: red;
        }

        ul li:last-child {
            background: blue;
            /* 添加一个相对定位 */
            position: relative;
            top: -100px;
            left: 200px;
        }
    </style>
</head>

<body>
    <!-- 相对定位是相对于他原来的位置进行移动，移动后原来的空间还是存在 -->
    <ul>
        <li></li>
        <li></li>
    </ul>
    3
</body>

</html>